This invention is related generally to surveillance systems, and more particularly to a wireless microphone for use with an in-car video system.
Vehicle-mounted surveillance systems, also termed in-car video systems, are seeing increased use in the security industry and law enforcement community as an effective means to provide an indisputable video and audio record of encounters involving officers and citizens. In these systems, a video camera is typically mounted on the police car's dashboard or windshield and is generally arranged to have a field of view of the area to the immediate front of the car. The field of view approximately corresponds to what an officer would see when seated in the car's front seat.
The video camera is operably coupled to a recording device, such as a video cassette recorder (“VCR”), mounted in the police car, often in the trunk. A videotape recording may be started manually by the officer, or in some systems, the videotaping is started automatically when, for example, the officer activates the police car's emergency systems (such as overhead lights and/or sirens), or when a vehicle speed-measuring radar unit is operated.
In some in-car video systems, the VCR may start recording when the officer activates the wireless microphone. Security schemes may also be used where the VCR starts recording only when it receives a predetermined code at a certain RF frequency from the wireless microphone. Inadvertent triggering from stray RF signals is thus avoided. A visual indicator to verify that a videotape recording is being made may be displayed on an indicating device mounted on the car (such as a light in the car's front grill or windshield) that can be seen by the officer at a distance (for example, when the officer is located in the proximity of a stopped car).
In-car video systems serve to enhance prosecution of traffic, DWI/DUI and controlled dangerous substances offenses (to name just a few) by contributing detailed graphical and auditory evidence in a time-sequential manner that is inherently unbiased and objective. Such evidence is a valuable adjunct to eyewitness and officer testimony. In addition, as with other quality-improvement initiatives where conduct is surveyed and recorded, in-car video system usage has been shown to assist in the maintenance of high professional standards among law enforcement personnel. Police-community relations have improved and citizen complaints of police misconduct have lessened in many jurisdictions where in-car video systems are used, often as a result of the inherently high-quality evidence provided by such systems. Videos taken with in-car video systems are also valuable training aids to law enforcement personnel.
Videotape evidence is protected (and the evidentiary chain of custody readily established) because the video cassette recorder and video recording medium (i.e., videotape) are typically “locked”, often both mechanically and electronically, within a tamperproof security enclosure in the car that is only accessible by law enforcement command personnel. In addition, the in-car systems are configured to prevent erasure or over-recording of a recorded encounter to ensure the integrity of the videotaped evidence. In-car video systems may superimpose time and date stamps on the recorded video image as a further enhancement to the evidentiary strength of the videotape.
In-car video systems generally employ a wireless microphone carried on the person of a law enforcement officer to record an audio soundtrack that accompanies the visual scene captured on videotape. The audio soundtrack is an extremely valuable complement to the recorded video because it acts as a transcript of the what was said, by whom and when. In some cases, the audio soundtrack is more valuable as evidence than the visual record because issues pertaining to consent, admissions, and state-of-mind of the suspect and/or officer (to cite just a few examples) may be resolved more effectively by the audio record. In some systems, additional wired microphones may be deployed in other locations within the car, such as the rear-seat passenger area, to record sounds and conversations emanating from those locations.
While current in-car video systems perform very well in many applications, there have been instances where officers have inadvertently failed to turn on the wireless microphone during an encounter or traffic stop even though the videotaping may be properly activated. Thus, a valuable piece of the evidentiary record is lost. Additionally, while car-mounted visual recording status indicators are very satisfactory in most situations, there may be times when the car-mounted indicator is out of the line of sight of the officer, or is obscured by weather conditions. Lost or damaged wireless microphones may also present a logistical challenge to some departments since each wireless microphone must be matched to a particular in-car video system in some systems in order to enable secure transmission from the wireless microphone.